1. Field
This disclosure relates to a recording medium in which information is recorded, and more particularly to a disk-shaped recording medium, and a disk cartridge which stores a plurality of disk-shaped recording media in a stacked manner.
2. Description of the Related Art
An optical disk includes a substrate and a cylindrical portion mounted on a center portion of the substrate and having a through hole. As one example of the optical disk, for example, there has been disclosed an optical disk where a notched portion is formed on an outer diameter side of a cylindrical portion (refer to Unexamined Japanese Utility Model Publication No. 1-103022, for example). As another example of the optical disk, there has been disclosed an optical disk where a label printing region is formed on one surface of the optical disk (refer to Unexamined Japanese Patent Publication 5-198015).